Only way to counteract bots is to make everything in the game untradeable, and having a queue system where you were put into parties at random and couldn't do anything in a premade group. But then you have a terrible game.

They used to be very visible at the start of the game, including spamming the /shout chat so it was basically unusable. Now bots tend to only spam certain gil selling sites around main hubs, and they warp around underground to do MSQ stuff, always as blm lalafell